1. Field of the Invention
This invention relates to a process for preparing graft and/or block copolymers. More particularly, this invention relates to a process for preparing block and/or graft copolymers of polyphenylene oxides and polyesters. Block and/or graft copolymers prepared in accordance with the process of this invention are capable of being fabricated into useful shaped articles of manufacture, e.g., films, molded articles, tapes, housings, ribbons, rods, laminates, panels, composites.
2. Description of the Prior Art
Polymer compositions are disclosed in the prior art as having many and varied uses in industrial and commercial applications. For example, these polymers can be fabricated into useful shaped articles, as for example, films, panels, gears, housing, skate boards and the like, through use of conventional molding and fabrication techniques.
The utility of a particular polymer for a particular application is very much dependent on the physical properties of the polymer. For example, polymers having increased molecular weights can be used in the formation of fibers and molded articles having superior properties. Fibers and molded articles made from such polymers have increased tensile strength, durability and impact resistance. Accordingly, processes for increasing the molecular weight of various polymers are valuable procedures in tailoring such polymers for optimization of such-properties.
Similarly, various functional groups and polymer side chains, as well as the structural conformation of certain polymers, are factors which affect the physical characteristics of polymers and thus are also critical to the utility of these polymers. Thus, procedures for varying and controlling these functional groups, side chains and structural conformations are also valuable tools in tailoring polymers for specific uses and as such are valuable tools to those of skill in the polymer art.
Organophosphites such as triphenylphosphite are known to cause reaction of polymer blends of nylons and polyester such as nylon 6/poly(ethylene terephthalate) and nylon 6/poly (butylene terephthalate) to form graft or block copolymers. For example, U.S. Pat. No. 4,417,031 and S. Aharoni, Polymer Bulletin, 10 pp. 210-214 (1983) disclose a process for preparing block and/or graft co-polymers by forming an intimate mixture of a phosphite compound, two or more polymers at least one of which includes one or more amino functions, as for example nylon, and at least one of the remaining polymers includes one or more carboxylic acid functions as for example a polyester.
Moulding material also containing a polyphenylene ether, a polyester such as polyethylene terephthalate and/or polybutylene terephthalate and from 5 to 15% of one or more flame proofing agents selected from among alkali metal or alkaline earth metal phosphates, high-boiling phosphoric acid esters, phosphoric acid esters, phosphinic acid esters, phosphonous acid esters or organic phosphine oxides are known. U.S. Pat. No. 4,672,086 indicates that these moulding materials are self-extinguishing.
Compositions of polyphenylene oxide and thermoplastic plastic polymers are known. In particular, polyphenylene oxide and polyamides compositions have been made as indicated in the U.S. Pat. Nos. 3,379,792 and 4,338,421. Such compositions are brittle unless other additives are incorporated into the compositions.
Patents such as U.S. Pat. No. 4,315,086 and European Patent Application 0,129,825 disclose compositions of polyphenylene oxide, also known as polyphenylene ether, and polyamides. These disclosures indicate that it is known to include an additional additive to enhance the properties of the composition. It is conjectured that such an additive provides a reactive linkage between the polyphenylene oxide and the polyamide. This linkage has been presumed to be a graft linkage.
It is known that the impact resistance of thermoplastic polymers such as polyamide as for example nylon 6, and polyesters as for example poly(ethylene terephthalate) can be improved by blending with elastomeric polymers. It is also known to add elastomeric or rubbery polymers to blends of polyphenylene oxide and polyamides where such compositions contain grafting agents. This is disclosed in U.S. Pat. No. 4,325,086.
International Application PCT/US86/01511 and U.S. Pat. No. 4,654,405 teach blends of functional polyphenylene oxides, polyamides, and impact modifiers such as polystyrene-polybutadiene-polystyrene.